Exemplary embodiments of the invention relate to a transmission device for a motor vehicle and to a motor vehicle comprising the transmission device.
A transmission device for a motor vehicle is known from DE 10 2015 104 778 A1, comprising: a final drive; a planetary gearset having at least one first transmission element formed by a ring gear, at least one second transmission element and at least one third transmission element; and at least one brake element for lock-braking at least one of the transmission elements of the planetary gearset.
A transmission device for a motor vehicle is known from generic DE 694 05 202 T2, comprising: a final drive; and a planetary gearset having a ring gear with external teeth for delivering a drive torque, at least one second transmission element and at least one third transmission element that is coupled to the final drive, the final drive being arranged radially inside the planetary gearset.
Furthermore, in transverse assemblies for motor vehicles, a final drive, in particular a ball differential, is generally integrated into a final drive wheel. This specifies that only one ratio is accommodated between a final drive pinion and the final drive. If a range group, for example, for a low range and a high range is integrated on the axle, this always occurs by means of a PTU connected downstream.
Exemplary embodiments are directed to advantageously and compactly accommodating an advantageous multispeed design into an existing installation space of the final drive and around the final drive.
According to an aspect of the invention, a transmission device for a motor vehicle comprises: a final drive; a planetary gearset having at least one first transmission element, which is formed by a first ring gear and has external teeth for delivering a drive torque, at least one second transmission element and at least one third transmission element that is coupled to the final drive; and at least one brake element for lock-braking at least one of the transmission elements of the planetary gearset. Preferably, the brake element is provided for lock-braking the second transmission element of the planetary gearset.
The “planetary gearset” should be understood to be, in particular, as a unit comprising a first sun gear, the first ring gear and at least one planet gear that is guided on a circular path around the sun gear by a first planet carrier.
According to an aspect of the invention, the final drive is designed as a planetary differential comprising a second ring gear, a second sun gear and a second planet carrier, which drive is arranged radially inside the planetary gearset and is arranged in a gearwheel plane with the planetary gearset.
The gearwheel plane is a plane arranged perpendicularly to the rotational axes of gears of the gearwheel plane. The gears belonging to the gearwheel plane are the first sun gear, the first ring gear, the planet gears of the first planet carrier, the second sun gear, planet gears of the second planet carrier, and the second ring gear. The rotational axes of the gears belonging to the gearwheel plane are arranged in parallel. The planetary differential being arranged in the gearwheel plane with the planetary gearset is a feature whereby the gearwheel plane intersects the first sun gear, the first ring gear, the planet gears of the first planet carrier, the second sun gear, planet gears of the second planet carrier, and the second ring gear.
This allows a very advantageous overall system consisting of a multispeed transmission comprising the planetary gearset, and the final drive. In particular, a multispeed design can be advantageously compactly accommodated into an existing installation space around the final drive. Particularly advantageously, a range group can be integrated upstream of the final drive, in particular into a final drive gear. Therefore, all gears can be reduced if necessary, which leads to higher output torques. In the crawl mode of operation, this is decisive for the engine operating points and cooling, for example. Furthermore, loading of the shift element can also be minimized. In particular, a PTU connected downstream can thus be omitted. Furthermore, installation space can be saved by a planetary differential being used instead of, for example, a ball differential, above and/or around which planetary differential a planetary gearset can advantageously be stacked. As a result, an advantageously compact design can be achieved. In this context, a “final drive” should be understood to be, in particular, a mechanism of a motor vehicle provided for transmitting a force of a drive unit of the motor vehicle to the axle of the drive wheels of the motor vehicle. Preferably, the final drive is provided for transmitting a force from the gearbox to the shaft of the drive wheels of the motor vehicle. Preferably, the final drive is formed by a differential gear, for example.
Advantageously, the planetary gearset has exactly one stationary ratio. Furthermore, a “brake element” in this context should be understood to be, in particular, a shift unit arranged so that it can act between a planetary gearset and a transmission housing, in particular between at least one transmission element of the planetary gearset and the transmission housing, and is provided for connecting, with a fixed rotational relationship, the rotatable coupling element thereof, which can be rotated independently of the transmission housing in an open state, to the coupling element thereof which is connected to the transmission housing with a fixed rotational relationship, in a closed state. Preferably, the rotatable coupling element is permanently connected to the transmission element of the planetary gearset with a fixed rotational relationship. “Connected with a fixed rotational relationship” should be understood to be, in particular, a connection in which a power flow, averaged over a complete rotation, is transmitted with an unadjusted rotational torque, an unadjusted rotational direction, and/or an unadjusted rotational speed. In this context, a “planetary differential” should be understood to be, in particular, a final drive, in particular a differential gear, which comprises at least one planetary gearset for transmitting a force of a drive unit of the motor vehicle to the axle of the drive wheels of the motor vehicle. Preferably, the planetary gearset is provided for transmitting a force from the gearbox directly to the shafts of the drive wheels of the motor vehicle. “Provided” should be understood to mean in particular specially programmed, designed and/or equipped. Since an object is provided for a particular function, it should in particular be understood that the object accomplishes and/or carries out this particular function in at least one application state and/or operating state.
According to an aspect of the invention, the transmission device comprises a locking element provided for interlocking at least two transmission elements of the planetary gearset. Preferably, the locking element is provided for interlocking exactly two transmission elements of the planetary gearset. Preferably, the locking element is formed by a clutch. Preferably, the locking element is formed by a clutch having at least one locking state. In particular, an advantageously compact arrangement of the transmission device with advantageous shiftability can thus be achieved. In particular, an advantageous multispeed design can be achieved. In this context, a “locking element” should be understood to be, in particular, a clutch having at least one locking state. In this context, a “clutch” should be understood to be, in particular, a shift unit arranged in a power flow between two planetary gearsets or between at least two transmission elements of the planetary gearset and provided for interconnecting the two rotatably mounted coupling elements thereof, which can be rotated independently of one another in an open state, with a fixed rotational relationship in a closed state. Preferably, every coupling element is, in each case, permanently connected to a transmission element with a fixed rotational relationship.
According to an aspect of the invention, the final drive is designed as a planetary differential comprising a double planet. Preferably, the planetary gearset of the planetary differential is therefore designed as a double planetary gearset. In particular, an advantageous final drive that is designed as a planetary differential can thus be provided.
According to an aspect of the invention, the third transmission element of the planetary gearset is formed by planet carriers and are permanently connected to the ring gear of the final drive with a fixed rotational relationship. In particular, an advantageously compact arrangement of the transmission device can thus be achieved. In particular, delivering torque to the final drive in an advantageous manner can thus also be achieved.
According to an aspect of the invention, the locking element is provided for interlocking the first transmission element, which is designed as a ring gear, of the planetary gearset and the third transmission element, which is designed as a planet carrier, of the planetary gearset. Preferably, a coupling element of the locking element is permanently connected to the first transmission element with a fixed rotational relationship and a coupling element of the locking element is permanently connected to the third transmission element with a fixed rotational relationship. Particularly advantageously, a ratio of i=1 can therefore be achieved by means of the planetary gearset. Preferably, the planetary gearset can therefore be advantageously bypassed.
The aim is also achieved by the brake element being provided for braking the second transmission element, which is designed as a sun gear, of the planetary gearset. For this purpose, the rotatable coupling element of the brake element is preferably permanently connected to the second transmission element with a fixed rotational relationship. In particular, an advantageous ratio can thus be achieved.
According to an aspect of the invention, the third transmission element of the planetary gearset is formed by a sun gear and is permanently connected to the ring gear of the final drive with a fixed rotational relationship. In particular, an advantageously compact arrangement of the transmission device is thus made possible. In particular, delivering torque to the final drive in an advantageous manner can thus be achieved. In particular, an advantageous arrangement of the final drive inside the sun gear can be achieved. An advantageously narrowly designed transmission device can thus be provided.
According to an aspect of the invention, the third transmission element of the planetary gearset is integral with the ring gear of the final drive. Preferably, the final drive, designed as a planetary differential, and the planetary gearset are arranged in a stack. Preferably, the third transmission element, which is in particular designed as a sun gear, and the ring gear of the final drive are a single gear. In particular, an advantageously compact arrangement of the transmission device is thus made possible. Furthermore, the number of components can therefore be minimized.
According to an aspect of the invention, the brake element is provided for braking the second transmission element, which is designed as a planet carrier, of the planetary gearset. In particular, an advantageous ratio can thus be achieved. In particular, a reversal of the rotational direction can be achieved. In particular, a mechanical reverse gear can thus be provided.
According to an aspect of the invention, the locking element is provided for interlocking the first transmission element, which is designed as a ring gear, of the planetary gearset and the third transmission element, which is designed as a sun gear, of the planetary gearset. Preferably, a coupling element of the locking element is permanently connected to the first transmission element with a fixed rotational relationship and a coupling element of the locking element is permanently connected to the third transmission element with a fixed rotational relationship. Particularly advantageously, a ratio of i=1 can therefore be achieved by means of the planetary gearset. Preferably, the planetary gearset can therefore be advantageously bypassed.
In this context, the terms “axial” and “radial” relate to a main rotational axis of the transmission device, and therefore the expression “axial” denotes, in particular, a direction extending in parallel with or coaxially to the main rotational axis. Furthermore, the expression “radial” hereinafter denotes, in particular, a direction that extends perpendicularly to the main rotational axis.
Combining the transmission device according to the invention with an electric motor in order to form an electric drivetrain is particularly advantageous. A particularly compact electric drivetrain results from the electric motor and the transmission device being arranged such that an electric motor output gear that is arranged coaxially to a rotor of the electric motor meshes with the external teeth of the first ring gear of the planetary gearset. The electric motor output gear is therefore advantageously arranged in the gearwheel plane with the planetary gearset and the final drive.
Further advantages can be found in the following description of the drawings. Two embodiments of the invention are shown in the drawings. The drawings, the description of the drawings and the claims contain numerous features in combination. A person skilled in the art will expediently also consider the features individually and combine them to form meaningful further combinations.